Whipstock liner

ABSTRACT

A liner system has a setting collar at one end and is adapted for insertion into a well bore. The setting collar is adapted to couple with a liner running tool. A whipstock surface is provided on the setting collar and adapted to deflect a drilling string in drilling a lateral well bore off of the first well bore. A method of forming a well system includes forming a first well bore; installing a first liner in the first well bore, the first liner having a first whipstock surface adapted to deflect a drilling string; and then forming a second well bore extending from the first well bore by deflecting a drilling string through contact with the first whipstock surface.

This application claims the benefit of U.S. Provisional Application No.60/697,638, filed Jul. 8, 2005.

TECHNICAL FIELD

The present invention relates to well bore patterns, and moreparticularly to forming one or more lateral well bores off a firstdrilled well bore.

BACKGROUND

In some wells, a liner can be used to prevent the wall of a well borefrom caving or to filter solids (particulate or larger) from enteringthe well bore. Liners can also be run to isolate one or moresubterranean zones, for example, to protect fresh-water formations,isolate a zone of lost returns or isolate formations with significantlydifferent pressure gradients. Liners are usually manufactured from plaincarbon steel, but may be specially fabricated of stainless steel,aluminum, titanium, fiberglass and other materials.

In some cases, it is desirable to drill a second well bore from a firstwell bore, i.e., a lateral. One manner of drilling the second well boreinvolves a whipstock. Whipstocks include an inclined wedge placed in awell bore that forces the drill bit to start drilling in a directionaway from the well bore axis. The whipstock has a hard surface so thatthe bit will preferentially drill through either casing or rock ratherthan the whipstock itself. Whipstocks may be oriented in a particulardirection if needed, or placed into a well bore blind, with no regard tothe direction they face. Most whipstocks are set on the bottom of thehole or on top of a high-strength cement plug or a whipstock anchorpacker (e.g., a special-purpose packer placed in the casing to permit asidetrack operation), but some are set in an open well bore. When theoperations involving the whipstock are complete, the whipstock is oftenretrieved from the well bore.

SUMMARY

The present invention relates to well bore patterns, and moreparticularly to forming one or more lateral well bores off a firstdrilled well bore.

In one aspect, a device includes a liner having a setting collar at oneend, the setting collar adapted to couple with a liner running tool, thesetting collar further adapted to attach a liner tubing; and a whipstocksurface on the setting collar adapted to deflect a drilling string.

In another aspect, a liner system includes: a first length of linertubing extending from a first end to a second end; and a setting collaradapted to couple with a liner running tool, the setting collarincluding a whipstock surface adapted to deflect a drilling string. Thesetting collar is coupled to the first end of the first length of linertubing.

In another aspect, a method of forming a well system includes: forming afirst well bore; installing a first liner in the first well bore, thefirst liner having a first whipstock surface adapted to deflect adrilling string; and then forming a second well bore extending from thefirst well bore by deflecting a drilling string through contact with thefirst whipstock surface.

Embodiments can include one or more of the following features.

In some embodiments, the liner includes a length of liner tubing. Insome instances, a threaded connection couples the setting collar to thelength of liner tubing. In some instances, a first inner diameter of thesetting collar at least as large as a second inner diameter of the linertubing. In some instances, the liner tubing is selected from the groupconsisting of solid liner tubing, apertured liner tubing, and othertypes of liner tubing.

In some embodiments, the whipstock surface is at least partially definedby additional material coupled to the end of the setting collar.

In some embodiments, the whipstock surface is defined at an end of thesetting collar and is formed at a an angle to a longitudinal axis of thesetting collar. In some instances, the angle is between 2 and 45 degrees(e.g., about 3 degrees, between 10 and 20 degrees, and/or about 15degrees).

In some embodiments, the whipstock surface is defined by an end portionof setting collar sidewalls. In some instances, the end portion of thesetting collar sidewalls has a first sidewall thickness than is greaterthan a second sidewall thickness of a second portion of the settingcollar sidewalls. In some instances, the first sidewall thickness isgreater than a third sidewall thickness of a length of liner tubingcoupled to the setting collar. A threaded connection can couple thesetting collar to the first length of liner tubing. A first innerdiameter of the setting collar can be at least as large as a secondinner diameter of the liner tubing.

In some embodiments, liner systems also include a second length of linertubing, the second length of liner tubing attached to the second end ofthe first length of liner tubing.

In some embodiments, the first liner includes a first setting collar(e.g., a setting collar is adapted to couple with a liner running tool)attached to a length of liner tubing. In some instances, installing aliner includes orienting the first whipstock surface by rotating thefirst setting collar. Rotating the first setting collar can includeengaging the first setting collar with torque fins on the liner runningtool.

In some embodiments, methods also include installing a second liner inthe second well bore, the second liner having a second whipstock surfaceon the second setting collar adapted to deflect a drilling string. Insome instances, methods also include forming a third well bore bydeflecting a drilling string through contact with the second whipstocksurface. The third well bore can extend from the first well bore

An advantage of one or more implementations is that the whipstocksurface is integrated with the setting collar of the liner. Thus, aseparate whipstock need not be provided. As the whipstock surfaceresides at the end of a liner, the spacing between laterals is notlimited by the size of a separate whipstock tool. In other words,multiple whipstock surfaces can be positioned closer to one another in awell bore than multiple separate whipstocks, because the whipstocksurfaces residing at the end of a liner take up less space. As a result,multiple lateral well bores can be diverted from the original at moreclosely spaced intervals. For example, one liner can be positionedadjacent, and in some instances within a few inches of or in contactwith, the whipstock surface of another liner. This allows the firstliner to communicate flow into the second string and reduces the chanceof the well bore plugging if it collapses. In some implementations, thewhipstock surface maintains its position and orientation within the wellbore by reacting against the liner tubing which may be frictionally heldin the well bore. In some implementations, there are no moving partsassociated with a gripping mechanism to fail. Also, because of the lackof moving parts, the system is inexpensive to construct.

Another advantage of one or more implementations is increased drillingefficiency because of a reduced number of trips into and out of the wellbore. For example, a well system with single lateral well bore divergingfrom a horizontal well bore can be formed with only three trips into andout of the well system using the devices, systems, and methods describedabove. First, a drill string can be used to form the horizontal wellbore extending from an articulated well bore. Second, after the drillstring is withdrawn, a working string can be used to install a linerwith a setting collar with a whipstock surface in the horizontal wellbore. The liner is positioned such that the setting collar is disposedat the point the lateral well bore will be formed. Third, after theworking string is withdrawn, the drill string travels back through thearticulated well bore and horizontal well bore until it is deflected bythe whipstock surface on the setting collar of the liner in thehorizontal well bore. After forming the lateral well bore, the drillstring is withdrawn. In contrast, use of a separate whipstock requiresadditional trips into and out of the well bore by the working string toplace and retrieve the whipstock (e.g., after the liner is installed inthe horizontal well bore and after the lateral well bore is formed).

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic partial side cross-sectional view of anillustrative liner system constructed in accordance with the conceptsdescribed herein.

FIG. 2 is a schematic side cross-sectional view of an illustrative wellsystem constructed in accordance with the concepts described herein.

FIG. 3 is a schematic plan view of the illustrative well system of FIG.1.

FIG. 4 is a schematic side cross-sectional view of the illustrative wellsystem of FIG. 2 during its construction in accordance with the conceptsdescribed herein.

FIG. 5 is a schematic side cross-sectional view of the illustrative wellsystem of FIG. 2 during its construction in accordance with the conceptsdescribed herein.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Referring to FIG. 1, an illustrative liner system 10 constructed inaccordance with the concepts described herein is depicted depending froma liner running tool 12 in a well bore 14. The illustrative liner system10 includes a tubular setting collar 16 coupled to one or more lengthsof liner tubing 18. In one instance, the tubular setting collar 16 iscoupled to an adjacent length of liner tubing 18 with a threadedconnection. The liner tubing 18 can be one or more lengths of solidtubing, apertured tubing, and other types of liner tubing.

Although there are numerous liner running tools that can be used inaccordance with the concepts described herein, an illustrative linerrunning tool 12 is depicted in FIG. 1. The illustrative liner runningtool 12 includes a body portion 28 that is adapted to couple to (anddepend from) a working string 26. The body portion 28 is at leastpartially received within the interior of the setting collar 16. One ormore radially extendable/retractable dogs 20 are positioned about thebody portion 28. In the extended position, the dogs 20 protrude from theexterior of the body portion 28. FIG. 1 depicts the dogs 20 extendedinto a corresponding groove 22 in the interior of the setting collar 16.The dogs 20 abut a downwardly facing shoulder 24 of the groove 22 andsupport the weight of liner system 10. When retracted, the dogs 20reside out of the groove 22. In one instance, the dogs 20 are biased tothe radially extended position, and can be retracted by application ofhydraulic pressure through the interior of the liner running tool 12.Thus, to release the dogs 20 from the groove 22 and the liner runningtool 12 from the setting collar 16, hydraulic pressure is appliedthrough the interior of liner running tool 12. In other instances, thedogs 20 may be extended or retracted by one or more of mechanicalmanipulation via the working string 26, hydraulic pressure, electricpower or other mechanism. When the dogs 20 are released from the groove22, the liner running tool 12 can be withdrawn from the setting collar16.

The liner running tool 12 further includes one or moreextendable/retractable torque fins 28 positioned about the body portion28. In the extended position, the torque fins 28 protrude from theexterior of the body portion 28. FIG. 1 depicts a torque fin 28 extendedinto a corresponding longitudinally (with respect to the setting collar16) oriented slot 30 in the interior of the setting collar 16. Thenumber of slots 30 can correspond to the number of torque fins 28. Whenthe liner running tool 12 is rotated relative to the setting collar 16,the torque fin 28 abuts one or the other sidewall 32 of the slot 30, andcause the setting collar 16 to rotate with the liner running tool 12.When retracted, the torque fins 28 reside out of the slots 30, and theliner running tool 12 can rotate in the setting collar 16. In oneinstance, the torque fins 28 are spring biased to the radially extendedposition, and include a sloped upper surface 34. As the liner runningtool 12 is drawn upward in the setting collar 16, the sloped uppersurface 34 bears against the upper wall 36 of the slot 30 and wedges thetorque fins 28 to the retracted position and out of the slots 30.Thereafter the running tool 12 may be withdrawn from the setting collar16. In other instances, the torque fins 28 may be extended or retractedby one or more of mechanical manipulation via the working string 26,hydraulic pressure, electric power or other mechanism.

The tubular setting collar 16 has a whipstock surface 40 on its upperend. As is discussed in more detail below, the whipstock surface 40operates to deflect drilling operations to deviate from a longitudinalaxis of the setting collar 16. The longitudinal axis of the settingcollar 16 is substantially parallel or coincides with the longitudinalaxis of a portion of the well bore (e.g. well bore 14) in which thesetting collar 16 resides. The whipstock surface 40 is defined at theend of the setting collar 16 and formed at a specified angle θ to thelongitudinal axis of the setting collar 16. The specified angle θ isselected based on the desired angle of departure of the drillingoperations from the longitudinal axis of the well bore. In someinstances, at least a portion of the whipstock surface is at an acuteangle to a longitudinal axis of the setting collar. For example, in oneinstance, the whipstock surface 40 is formed at a 15° angle to thelongitudinal axis of the well bore 14. In other instances, the whipstocksurface 40 can be formed at shallower or steeper angles. For example, inanother instance, the whipstock surface 40 is formed at a 3° angle tothe longitudinal axis of the well bore 14. In certain implementations,the whipstock surface 40 has two or more angles. For example, in oneinstance, the whipstock surface 40 has an initial angle of 15° andsubsequently an angle of 3° to the longitudinal axis of the well bore14.

In certain implementations, the whipstock surface 40 is defined by theend walls 42 of the setting collar 16. Accordingly, the whipstock isintegral to the liner tubing 18 in contrast to a conventional whipstockthat is coupled to an interior of a liner or casing. To this end, thesetting collar 16 may have an increased sidewall thickness 44 about theend walls 42. In some instances, this sidewall thickness 44 is greaterthan the sidewall thickness 46 of the liner tubing 18. In one instance,the setting collar 16 has an outer diameter approximately equal to theouter diameter of a stock sized collar for use with the size of linertubing 18 used, but has an inside diameter sized to receive a stock sizeliner running tool 12 for running a smaller size of liner tubing. Forexample, for a system with 4.5 inch (114.3 mm) nominal outer diameterliner tubing 18, the setting collar 16 can have 5.0 inch (127 mm)nominal outer diameter (i.e. approximately equal to the standard sizecasing collar), but have an inner diameter sized to accept a stock linerrunning tool 12 configured for running a 3.5 inch (88.9 mm) nominalouter diameter liner tubing 18. In other implementations, additionalmaterial may be coupled to the end of the setting collar 16 to define awhipstock surface 40. The inner diameter of the setting collar 16 isequal to or greater than the inner diameter of the liner tubing 18. Forexample, in some instances, a smallest inner diameter of the settingcollar is at least as large as a smallest inner diameter of the linertubing.

In certain implementations, the whipstock surface 40 can be harder thanthe remainder of the setting collar 16. In one instance, the whipstocksurface 40 is steel that has been surface hardened. In other instances,a hardened surface is deposited on the whipstock surface 40 in additionto, or as an alternative to, the surface hardening.

In some embodiments, the setting collar 16 and whipstock surface 40 areof one-piece construction (e.g., the whipstock surface is formeddirectly on the setting collar). In some embodiments, the setting collar16 and whipstock surface 40 are of unitary multi-piece construction(e.g., the whipstock surface can be formed on a separate work piece thatfixedly attached to the setting collar so that the setting collar andwhipstock-bearing work piece are not separable downhole.

The liner running tool 12 enables the illustrative liner system 10 to beplaced in a well bore, such as well bore 14. To this end, the linerrunning tool 12 is coupled to a working string 26 and received in thesetting collar 16 of the illustrative liner system 10. The dogs 20 arechanged to the extended position to be received in the groove 22 of thesetting collar 16. If biased to the extended position, the dogs 20automatically snap into the groove 22. The liner system 10 is thereaftersupported from the liner running tool 12, as the dogs 20 bear againstthe shoulder 24 of groove 22. Additionally, the torque fins 28 of theliner running tool 12 can be aligned with the slots 30 in the settingcollar 16. When changed to the extended position, the torque fins 28 arereceived in the slots 30 and torsionally lock the liner running tool 12to the setting collar 16 (and thus illustrative liner system 10) torotate together. If biased to the extended position, the torque fins 28automatically snap into the slots 30 when aligned with the slots 30.Thereafter, the illustrative liner system 10 depends from the linerrunning tool 12, and is run into a well bore, such as well bore 14 as isdepicted in FIG. 4, on the working string 26. Once in the desiredlocation within the well bore and/or as the illustrative liner system ismoved into location in the well bore, the illustrative liner system 10can be rotationally oriented to align the whipstock surface 40 todeflect drilling operations in the desired orientation by rotating theliner running tool 12 via the working string 26. The liner running tool12 can then be released from the illustrative liner system 10 byactuating the dogs 20 to the retracted position (for example, byapplying hydraulic pressure through the working string 26 into theinterior of the liner running tool 12), actuating the torque fins 28 tothe retracted position (for example, by wedging sloped upper surface 34against the upper wall of the slot 36), and withdrawing the linerrunning tool 12 from the setting collar 16. The setting collar 16 andwhipstock surface 40 need not be attached (for example, by slips) to thewall of the well bore, because they are affixed to the liner tubing 18.The liner tubing 18, in turn, is frictionally held in the well bore 14.However, in some instances, the setting collar can include a linerhanger and/or can include a gripping assembly (e.g., slips). Thegripping assembly is actuable into gripping engagement with a wall ofthe well bore to anchor the setting collar, and liner tubing, in thewell bore.

FIG. 2 depicts an illustrative well system 100 constructed in accordancewith the concepts described herein. The well system 100 includes asurface well bore 110 and one or more secondary well bores 112 (threeshown) formed near to, and in some instances adjacent to, one another.The secondary well bores 112 define a well bore pattern. The surfacewell bore 110 extends either directly from the surface 116, or extendsfrom another bore, pit, shaft, fissure, cavity, or other feature (notspecifically shown) in communication with the surface 116. In FIG. 2,the surface well bore 110 is depicted as an articulated well bore havinga first portion 118, a second portion 120, and a curved portion 122connecting the first portion 118 and the second portion 120. The secondportion 120 extends into a subterranean zone 114. Although depicted asbeing substantially vertical, some or all of the first portion 118 maybe slanted, undulating, or otherwise not vertical. Likewise, althoughdepicted as being substantially horizontal, some or all of the secondportion 120 may be slanted, undulating, or otherwise not horizontal. Acasing 124 or other type of liner tubing may optionally be providedthrough at least a portion of the surface well bore 110. The casing 124may be provided, for example, to prevent collapse of the earth about thewell bore 110 and/or to isolate other subterranean zones through whichthe well bore 110 may pass from communicating with the well bore 110.FIG. 3 depicts the casing 124 extending from a wellhead 136 about thesurface 116 downward through the first portion 118, curved portion 122and into the second portion 120. In other instances, the casing 124 canextend solely in the first portion 118 or through the first portion 118and into the curved portion 122.

In one instance, the subterranean zone 114 is a coal seam. However, theconcepts described herein are applicable to other types of subterraneanzones. For example, the subterranean zone 114 can be an oil and gasformation, water producing formation, or other type of formation.

The illustrative well system 100 further includes a cavity 126 (anenlarged cavity is shown) formed in or near to the subterranean zone114. Other well systems formed according to the concepts describedherein can omit the cavity 126. In one instance, the cavity 126 isformed through a surface communicating cavity well bore 128 extendingeither directly from the surface 116, or from another bore, pit, shaft,fissure, cavity, or other feature (not specifically shown) incommunication with the surface 116. Therefore, the cavity 126corresponds to the location of an intersection between the surface wellbore 110 and the cavity well bore 128. The cavity 126 may have a largertransverse dimension than the cavity well bore 128, as is shown in FIG.2, or may have a transverse dimension that is smaller than orsubstantially equal to the transverse dimension of the cavity well bore128. Some or all of the cavity well bore 128 may be provided with acasing 130 or other type of liner tubing. The casing 130 may beprovided, for example, to prevent collapse of the earth about the wellbore 128 and/or to isolate other subterranean zones through which thewell bore 128 may pass from communicating with the well bore 128. InFIG. 2, the casing 130 is shown extending from a wellhead 132 at thesurface 116 to the cavity 126. The casing 130 may also be omitted. Thecavity 126 can also optionally be provided with a sump 134 that extendsdownward beneath the cavity 126. In operation of the illustrative wellsystem 100, the sump 134 functions to collect fluids and fines receivedin the cavity 126 to facilitate removal of the fluids (and sometimesalso the fines) to the surface 116. The inlet 144 of a pump 146 can beprovided in the sump 134 to pump the fluids from the sump 134 to thesurface 116. Alternately, the inlet 144 of the pump 146 can be providedwithin the cavity 126 or within the interior of the cavity well 128 topump fluids from the cavity 126 to the surface 116. An apertured linersection 152 may be provided in the cavity 126 and communication with theinterior of the cavity well bore 128. The cavity 126 may be filled withgravel or other particulate 148 (i.e. gravel packed) to help support thecavity 126 from collapse and to filter against passage of pieces of thesubterranean zone 114 to the surface 116.

The secondary well bores 112 are depicted as extending substantiallyhorizontal within the subterranean zone 114 that likewise extendssubstantially horizontal. The secondary well bores 112 need not behorizontal, and in other instances, one or more of the secondary wellbores 112, or portions thereof, may be vertical, slanted, undulating, orotherwise not horizontal. In one instance, one or more of the secondarywell bores 112 is slanted to follow the updip or the downdip of thesubterranean zone 114. One or more of the secondary well bores 112 may,alternately or additionally, have a shallow slope that causes fluidsreceived in the secondary well bores 112 to flow towards the cavity 126.

FIG. 2 depicts the secondary well bores 112 originating from the samelocation about the end of the second portion 120 of the surface wellbore 110. In other instances, one or more of the secondary well bores112 can originate from distinct locations within or apart from thesurface well bore 110 or subterranean zone 114. The secondary well bores112, or portions thereof, may be substantially parallel to other of thesecondary well bores 112 or may diverge from other of the secondary wellbores 112. In FIG. 2, the secondary well bores 112 are depicted asdiverging from one another near their origin and being substantiallyparallel to one another in a portion that intersects the cavity 126. Asis seen in FIG. 3, the secondary well bores 112 thereafter diverge andextend to a boundary of a specified access area 142 to more evenlyaccess, for example to drain, the specified access area 142. All of thesecondary well bores 112 may be substantially aligned in the samehorizontal, vertical or other plane, or one or more of the secondarywell bores 112 may reside at least partially out of plane with others ofthe secondary well bores 112.

It should be appreciated that the systems and methods of using theillustrative liner system 10 described herein are described with respectto the specific configuration of the illustrative well system 100 forconvenience of discussion only. The systems and methods described hereincan be applied equally to other configurations of well systems and wellbores. For example, other well systems may omit the cavity well bore,have different patterns of secondary well bores, or have other differentconfigurations.

One or more of the secondary well bores 112 is provided with anillustrative liner system 10 that extends through at least a portionthereof. The liner systems 10 may be provided, for example, to preventthe subterranean zone 114 from collapsing into the secondary well bores112. FIG. 2 depicts a liner system 10 provided in two of the completedsecondary well bores 112, and a liner 138 optionally excluding thewhipstock surface 40 installed the last installed liner system 10. Theliner systems 10 and liner 138 extend from about the second portion 120of the surface well bore 110 and through the cavity 126 continuing oninto the subterranean zone 114. The liner systems 10 and/or liner 138may further extend to the end of each of the secondary well bores 112.One or more of the liners 10, 138 and/or liner tubings 18 may beprovided with apertures 140 to allow passage of fluid between theirrespective exterior and interior. The liners 10, 138 and/or linertubings 18 may, in some instances, be jointed lengths of tubingconnected by collars 150. In other instances, the liners 10, 138 and/orliner tubings 18 may be continuous tubing. The liners 10, 138 and/orliner tubings 18 may be affixed or otherwise intended to reside in thesecondary well bores 112 for the life or a majority of the life of thewell system 100.

Turning now to FIG. 4, an illustrative method for forming well bores isdescribed with reference to the construction of illustrative well system100. In construction of the illustrative well system 100, the cavitywell bore 128 is drilled from the surface 116 to the desired location ofthe cavity 126 in or near the subterranean zone 114. If a sump 134 is tobe provided, the cavity well bore 128 may be drilled to extend below thedesired location of the cavity 126. In some instances, a casing 130 canbe positioned (and optionally cemented in place) in the cavity well bore128 above the location of the cavity 126. The cavity 126 is formedthrough the cavity well bore 128. In one instance, the cavity 126 isformed using hydraulic or mechanical under reaming processes. The cavity126 may be centered about the cavity well bore 128. As is seen in FIG.2, the cavity well bore 128 may be drilled so that the cavity 126 can beformed offset from a corner of the access area 142 (whether or not thecavity well bore 128 originates offset from a corner of the access area142).

The first portion 118 of the surface well bore 110 is drilled from aboutthe surface 116 towards the subterranean zone 114. The first portion 118may be located near a corner of the access area 142 (see FIG. 2).Directional drilling equipment 178 provided on a drill string 180 isthen used to drill the curved portion 122. In one instance, thedirectional drilling equipment 178 includes a downhole steerable motor,such as a mud motor coupled to an adjustable bend or fix bend, bent sub,accelerometer based inclinometer, and magnetic guidance tools. Thedirectional drilling equipment 178 is coupled to a drilling bit 176 suchthat the downhole steerable motor rotates the drilling bit 176. The bentsub points the downhole steerable motor and drilling bit 176 in adirection different from the axis of the preceding portions of the wellbore drilled (i.e. first portion 118) when the drill string 180 is notbeing rotating. When rotated by the downhole steerable motor, the drillbit 176 drills in the direction it points. Therefore, by orienting thedrill string 180 to point the bent sub in the desired direction, thedrill bit 176 drills the curved portion 122 of the surface well bore110. When the curved portion 122 is complete, the second portion 120 maybe drilled substantially straight (in one instance, substantiallyhorizontal) by rotating the entire drill string 180 while operating thedownhole steerable motor to rotate the drill bit 176. Rotating the drillstring 180 sweeps the bent sub through 360 degrees and the drill bit 176does not drill in a single direction off the well bore axis, but rathersweeps around with the bent sub and drills in a net direction that issubstantially straight. If the bent sub is adjustable, the angle of thebent sub can be set to 0 degrees relative to the axis of the well boreto drill a substantially straight well bore without rotating thedrilling string 180. Although described herein with respect to a slidingsteerable motor and bent sub, it is within the scope of the conceptsdescribed herein to use rotary steerable tools to directional drill.

In some instances, upon completion of all or some portion of the surfacewell bore 110, a casing 124 can be positioned (and optionally cementedin place) in the surface well bore 110 or portions thereof.

A first of the secondary well bores 112 is drilled extending from thesecond portion 120 of the surface well bore 110. In one instance, asshown in the figures, the first drilled secondary well bore 112 isdrilled substantially straight out from the end of the second portion120 of the surface well bore 110, through the cavity 126 and diagonallyto a distant corner of the specified access area 142 (FIG. 3). When thefirst drilled secondary well bore 112 is complete, a liner system 10 canbe positioned in the first drilled secondary well bore 112 using linerrunning tool 12 and working string 26. The whipstock surface 40 ispositioned about the desired origination (i.e. kick off) location of thesecond secondary well bore 112 to be drilled. Furthermore, as the linersystem 10 is being positioned in the first drilled secondary well bore112 or after the liner system 10 is in position, the liner running tool12 can be rotated via of the working string 26 to orient the whipstocksurface 40. In FIG. 4, the whipstock surface 40 is oriented to deflectdrilling operations downwardly from the longitudinal axis of the firstdrilled secondary well bore 112.

The second drilled secondary well bore 112 originates (i.e. kicks off)from the second portion 120 of the surface well bore 110. The seconddrilled secondary well bore 112 can be termed a lateral well bore to thesecond portion 120, because it deviates laterally from the secondportion 120. If drilled with the directional drilling equipment 178discussed above, the drill string 180 is rotated to orient the drill bit176 in the desired kick off direction. The drill bit 176 is rotated tobegin drilling, and the drill string 180 is pushed axially further intothe second portion 120. The drill bit 176 and drill string 180 deflectoff of the whipstock surface 40 into the sidewall of the well bore andbegin drilling the second drilled secondary well bore 112. Thereafter,the orientation of the drill string 180 may be periodically adjustedand/or the drill string 180 may be rotated as discussed above to controlthe desired path of the second drilled secondary well bore 112. Thesecond drilled secondary well bore 112 is drilled to diverge from(substantially vertically below) the first drilled secondary well bore112 for a distance, substantially track the first drilled secondary wellbore 112 for a distance, intersect the cavity 126, and as is seen inFIG. 3 further diverge from (substantially horizontally to the side) thefirst drilled secondary well bore 112 to an intermediate boundary of thespecified access area 142.

Turning now to FIG. 5, when the second of the secondary well bores 112is complete, the drill string 180 is withdrawn to the surface 116, and asecond liner system 10 is positioned in the second drilled secondarywell bore 112 using the liner running tool 12 and working string 26. Thesecond liner system 10 deflects off of the whipstock surface 40 of theliner positioned in the first drilled secondary well bore 112 as it isrun into the second drilled secondary well bore 112. The whipstocksurface 40 of the second liner system 10 is positioned about the desiredkickoff location of the third secondary well bore 112 to be drilled. InFIG. 5, the liner system 10 extends into the second portion 120 of thesurface well bore 110. As the liner system 10 is being positioned in thesecond drilled secondary well bore 112 or after the liner system 10 isin position, the liner running tool 12 can be rotated via the workingstring 26 to orient the whipstock surface 40. In FIG. 5, the whipstocksurface 40 is oriented to deflect drilling operations downwardly fromthe longitudinal axis of the second portion 120 of the surface well bore110.

The third drilled secondary well bore 112 kicks off from the secondportion 120 of the surface well bore 110. The third drilled secondarywell bore 112 can be termed a lateral well bore to the second portion120, because it deviates laterally from the second portion 120. Thedrill bit 176 is rotated to begin drilling and the drill string 180 ispushed axially into the second portion 120. The drill bit 176 and drillstring 180 deflect off the whipstock surface 40 into the sidewall of thewell bore and begin drilling the third drilled secondary well bore 112.The third drilled secondary well bore 112 is drilled to diverge from(substantially vertically below) the second drilled secondary well bore112 for a distance, substantially track the second drilled secondarywell bore 112 for a distance, intersect the cavity 126 and as is seen inFIG. 3 further diverge from (substantially horizontally to the side) thesecond drilled secondary well bore 112 to an intermediate boundary ofthe specified access area 142.

When the third drilled secondary well bore 112 is complete, a liner 138may be positioned within the third drilled secondary well bore 112. Theliner 138 may be provided to terminate in or about the casing 124. Inone instance, the liner 138 can be provided with a packer 144 thatsubstantially seals the annulus between the liner 138 and the casing124.

It should be clear from the discussion above that additional well boresbeyond the three secondary well bores 112 discussed above, or fewer wellbores can be formed.

Upon completion of the secondary well bores 112, the cavity 126 isgravel packed and the apertured liner section 152 is installed. The pumpinlet 144 can be positioned in the sump 134, the cavity 126 or thecavity well bore 128, and the pump 146 operated to withdraw fluid andfines to the surface while the subterranean zone 114 is produced eitherthrough the surface well bore 110 or through the cavity well bore 128.The setting collars 16 (and thus whipstock surfaces 40) of each linersystem 10 installed in the secondary well bores 112 remain in thesecondary well bores 112 indefinitely, and at least during production.Accordingly, fluids from the subterranean zone 14 that enter the linertubings 18 may flow through the interior of the setting collars 16 tothe surface if some or all of the fluids of the subterranean zone 114are produced through the surface well bore 110.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

1. A device comprising: a liner setting collar, the setting collaradapted to couple with a liner running tool, the setting collar furtheradapted to attach to a liner tubing; and a whipstock surface on thesetting collar adapted to deflect a drilling string.
 2. The device ofclaim 1 further comprising a length of liner tubing.
 3. The device ofclaim 2 wherein the length of liner tubing and liner setting collar arecoupled using a threaded connection.
 4. The device of claim 2 wherein asmallest inner diameter of the setting collar about the whipstocksurfaces is smaller than a smallest inner diameter of the liner tubing.5. The device of claim 2 wherein the liner tubing is selected from thegroup consisting of solid liner tubing, apertured liner tubing, andexpanded/expandable liner tubing.
 6. The device of claim 1 wherein thewhipstock surface is at least partially defined by additional materialcoupled to the end of the setting collar.
 7. The device of claim 1wherein the whipstock surface is defined at an end of the setting collarand wherein at least a portion of the whipstock surface is at an acuteangle to a longitudinal axis of the setting collar.
 8. The device ofclaim 7 wherein the angle is between 2 and 45 degrees.
 9. The device ofclaim 1 wherein the whipstock surface is defined by an end portion ofsetting collar sidewalls.
 10. The device of claim 9 wherein the endportion of the setting collar sidewalls has a first sidewall thicknessthan is greater than a second sidewall thickness of a length of linertubing coupled to the setting collar.
 11. The device of claim 1 whereinthe whipstock surface and setting collar are constructed as one piece ofmaterial.
 12. The device of claim 1 wherein the setting collar isadapted to remain attached to the liner tubing while the setting collaris in a well bore.
 13. A liner system comprising: a first length ofliner tubing extending from a first end to a second end; and a tubularbody adapted to couple with a liner running tool, the tubular bodyincluding a whipstock surface adapted to deflect a drilling string;wherein the tubular body is coupled to the first end of the first lengthof liner tubing.
 14. The liner system of claim 13 wherein the tubularbody is coupled to the first length of liner tubing using a threadedconnection.
 15. The liner system of claim 14 wherein a smallest innerdiameter of the tubular body about the whipstock surfaces is smallerthan a smallest inner diameter of the liner tubing.
 16. The liner systemof claim 13 further comprising a second length of liner tubing, thesecond length of liner tubing attached to the second end of the firstlength of liner tubing.
 17. The liner system of claim 13 wherein theliner tubing is selected from the group consisting of solid linertubing, apertured liner tubing, and expanded/expandable liner tubing.18. The liner system of claim 13 wherein the whipstock surface isdefined at an end of the tubular body and wherein at least a portion ofthe whipstock surface is at an acute angle to a longitudinal axis of thesetting collar.
 19. The liner system of claim 18 wherein the angle isapproximately 3 degrees.
 20. A method of forming a well system, themethod comprising: forming a first well bore; installing a first linerin the first well bore, the first liner having a first whipstock surfaceadapted to deflect a drilling string; and then forming a second wellbore extending from the first well bore by deflecting a drilling stringthrough contact with the first whipstock surface.
 21. The method ofclaim 20 wherein the first liner comprises a first setting collarattached to a length of liner tubing.
 22. The method of claim 21 whereinthe first setting collar is adapted to couple with a liner running tool.23. The method of claim 21 wherein installing a liner comprisesorienting the first whipstock surface by rotating the first settingcollar.
 24. The method of claim 23 wherein rotating the first settingcollar comprises engaging the first setting collar with torque fins onthe liner running tool.
 25. The method of claim 20 further comprisinginstalling a second liner in the second well bore, the second linerhaving a second whipstock surface adapted to deflect a drilling string.26. The method of claim 25 further comprising forming a third well boreby deflecting a drilling string through contact with the secondwhipstock surface.
 27. The method of claim 26 wherein the third wellbore extends from the first well bore.